RESUMEN
Objective To compare the changes in cardiac output (CO) and other hemodynamic parameters in patients undergoing gynecological laparoscopic surgery in head-down lithotomy position and Trendelenburg position. Methods Sixty patients were divided into head-down lithotomy group and Trendelenburg group. CO was recorded as baseline by a noninvasive cardiac output monitor NICOM? system after the placement of patients. These measurements were also acquired when the patients were placed in the 30° head-down tilt(T0)following pneumoperitoneum establishment.Stroke volume(SV), heart rate(HR)and CO were monitored at 1-minute intervals thereafter for a total of 10 minutes(T1-T10),and mean arterial pressure(MAP)and total peripheral resistance(TPR)were monitored every 5 minutes. Results The reduction of CO in head-down lithotomy group was greater than that in Trendelenburg group(T0:-31％±19％ vs.-9％±34％;T1:-32％±18％ vs.-16％±38％;T2:-33％± 19％vs.-16％±26％;T3:-32％±22％vs.-16％±28％;T4:-31％±18％vs.-12％±38％;T5:-30％± 17％vs.-14％±37％;T6:-31％±17％ vs.-14％±33％,all P<0.05)during the first 6 minutes. MAP at baseline in head-down lithotomy group was significantly higher than that in Trendelenburg group[(97±11) mmHg vs.(85±6)mmHg,P<0.05].MAP decreased in head-down lithotomy group at T0(-8％±16％) and increased in Trendelenburg group at T5 and T10(T5:9％±15％,T10:12％±18％). Conclusion CO reduction was greater in patients in head-down lithotomy position than that in Trendelenburg position group during the first 10 minutes after adjusting the position following pneumoperitoneum establishment.
RESUMEN
BACKGROUND: Propofol has gained widespread popularity but it should at least be questioned in the presence of heart rate lowering medications such as beta-blockers. Esmolol, due to its ultrashort action and cardioselective properties, has been shown to be safe and effective for use in intraoprative tachycardia and hypertension. The purpose of this study is to evaluate the hemodynamic effects of esmolol and propofol under isoflurane anesthesia in dogs. METHODS: Six-mongrel dogs were induced with thiopental, intubated and ventilated with a mixture of isoflurane (1-1.5 vol%) and oxygen. A pulmonary artery catheter was placed via femoral vein and the femoral artery was cannulated. After stabilization, baseline hemodynamic measurements (HR, MAP, CO, SVR) were obtained. Measurements were repeated 5 and 15 minutes after injection of propofol (2 mg/kg), esmolol (1 mg/kg), and additional esmolol (1 mg/kg) for 30 seconds. Data was analyzed by repeated measurement of ANOVA. P < 0.05 was considered significant. RESULTS: Propofol produced no change in heart rate, MAP, CO and SVR. Heart rate decreased significantly during esmolol administration and remained decreased up to 15 minutes after the injection whereas the MAP, CO and SVR showed no significant changes. CONCLUSIONS: We have demonstrated that the decrease in heart rate continued up to 15 minutes after esmolol administration. These findings suggest that concomittent administration of propofol and esmolol requires monitoring of the heart rate after a bolus intravenous injection of esmolol.